1. Field of the Invention
The present invention relates generally to ink cartridges. In particular, the present invention directed towards ink cartridges which may be used in combination with ink jet printers
2. Description of Related Art
Ink cartridges which are configured to be used in combination with ink jet printers are known in the art. In such known ink cartridges, it is possible to detect when the amount of ink in the ink cartridge is relatively low. For example, one known ink cartridge comprises a shutter mechanism which functions as a light-blocking portion, and a float on both edges of a level which is supported in the central portion of the ink reservoir element, such that it rotates about a support in the extender direction at the bottom of the ink reservoir element. Specifically, when there is a relatively large amount of ink in the ink reservoir element, the level will rotate due to an upwards movement of the float caused by buoyancy, thereby positioning the shutter near the bottom of the concave portion of the ink reservoir element, such that the shutter blocks the light that is emitted from a light emitting portion of an optical sensor. When the ink is removed from the ink reservoir element, the float drops and the level rotates, resulting in the shutter being positioned near the top portion of the concave portion, thereby stopping the blockage of light emitted from the light emitting portion. At this time, the light receiving portion of the optical sensor receives the light, and detects that the ink reservoir element is empty.
Nevertheless, in this known ink cartridge, a relatively large shutter mechanism is employed, and the shutter and the float are positioned on both edges of the level which is supported by the support member, which increases the size of the ink cartridge needed to house the shutter mechanism.